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Benjamin Bartels's avatar
Benjamin Bartels
Copper Contributor
Oct 30, 2018

On my teamed NIC, the MAC address keeps changing. How do I make it static?

Windows server 2016, 2 NIC ports, teamed with Microsoft Network Adapter Multiplexor Driver, no VMs, no VPNs, no load balancer.  After rebooting, the MAC address keeps changing (based on IPCONFIG /all).  Application software is based on MAC, so the application keeps failing after reboot.  

 

I've read that the Team uses the first NIC cards MAC, but I've also read that it may choose randomly based on load balancing.  I cannot view the MACs of the ethernet adapters.  I'm guessing this is because they're already teamed.

 

I couldn't find good documentation on how to set the MAC address of the NIC Team, so I'm making an assumption that I do the following: NICTeam > Properties > Configure > Advanced > MAC Address > Value... and set it to whatever 12 hex characters I want (000012345678).  Is this correct?  

 

Based on IPCONFIG, the NICTeam is presenting what looks like a standard MAC address.  I'm assuming it's grabbing this from one of the NICs.  If I use the method above and set the MAC to the same address, will I have conflicts in the future?  ...or is it safer just to use 000012345678?

Networking
Windows Server

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  • VINICIUSALVES-FINEPACK's avatar
    VINICIUSALVES-FINEPACK
    Copper Contributor
    Feb 14, 2024

    Hello everybody.
    I have a team of two NICs
    My application uses the MAC of the balance and as it keeps changing it is a big problem, so I thought about leaving the grouping with the MAC of one of the NICs, would that be a problem?
    Example 1
    NIC1 - 10:20:30:40:50:80
    NIC2 - 10:20:30:40:50:81
    GROUPING - 10:20:30:40:50:81

    Could I do this configuration?
    Or would I have to create a fictitious MAC for example?
    Example 2
    NIC1 - 10:20:30:40:50:80
    NIC2 - 10:20:30:40:50:81
    GROUPING - 10:20:30:40:50:82

    What is the best way to proceed?

  • Deleted's avatar
    Deleted
    Oct 30, 2018

    In my experience, the NIC team uses one of the MAC address of the underlying NICs but it usually stays the same. I have had duplicate MAC address messages but when I looked it up it was a non issue. I set the MAC address manually to get rid of that message. 

     

    "NICTeam > Properties > Configure > Advanced > MAC Address > Value... and set it to whatever 12 hex characters I want (000012345678).  Is this correct?  " 

     

    That's the way I did it. 

    • Benjamin Bartels's avatar
      Benjamin Bartels
      Copper Contributor
      Oct 30, 2018
      Thanks. It seemed to make sense, but with the lack of documentation, I didn't want to assume. I'll give it a try.
      • BradS's avatar
        BradS
        Copper Contributor
        Jul 27, 2022

        Benjamin Bartels 

        Hello, did you ever confirm if you can indeed set the NIC Team MAC address in Advanced setting and connectivity would still work?

        I have very similar server setup: two teamed NICs and appears that one of the NICs (first) seems to present its MAC as the MAC that is presented when querying IPCONFIG /ALL. I am not onsite with server, so hesitate making any change that would make the server unavailable, unless there is (tested) process.

        Yes, not seeing any instruction/details with Teaming on how the MAC is set and/or if it can be changed.

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